Looper



May 17, 1949. R. H. RANDALL LOOPER B-Sheets-Sheet 1 Filed Jan. 13, 1947 INVENTOR.

LIZ-x I May 17, 1949. R. H. RANDALL LOOPER 2 Sheets-Sheet; 2

Filed Jan. 13, 1947 INVENTOR.

Patented May 17, 1949 UNITED STATES PATENT OFFICE LOOPER Roy H. Randall, Manchester, Mich.

Application January 13, 1947, Serial No. 721,841

2 Claims. 1

This invention relates to loopers and is a continuation of my former application for Loopers, Serial No. 576,623, filed February 7, 1945, now abandoned.

An object of the invention is the provision of a looper adapted particularly for use on tacker heads employed in woolen mills for sewing cloth, the looper being manufactured with a minimum number of milling operations and so constructed that minimum wear will be had on the thread with minimum tension thereon, the body of the looper being cut away at one side to provide a clearance for the usual reciprocating needle which carries the thread.

A further object of the present invention is to provide an improved looper which may be used on a tacker head which will not impose tension on the thread at the same time the needle is maintaining tension, and which will permit the thread to be readily slipped or cast off of the looper in advance of the time the looper is entering a succeeding loop formed by the downwardly moving needle.

Another object of the invention is the provision of an improved looper of relatively narrow proportions and constructed in such a manner that the thread will not be under any severe strain durin the looping operation with all of the parts of the looper presentin relatively small surfaces to the thread so shaped that successive chain stitches may be formed at high linear travel of the cloth and which will permit a variation in the timing between it and the needle to occur without damage to the needle or skipping stitches.

A further object of the invention is the provision of an improved looper especially adapted for use on tacker heads in which relatively small surfaces are presented to the thread during the looping operation, said looper being provided with a longitudinal groove at one side thereof to provide a clearance for a reciprocating needle carrying a thread and to aid in maintaining the thread in proper position so that the trailing end of the looper can engage the thread at one side to cast the same oil. of the looper.

To these and other ends my invention has for its object to provide further improvements in construction, all as will be fully described in the accompanying specification, the novel features thereof being set forth in the appended claims.

In the drawings:

Figure 1 is a view in perspective of a tacker head showing my improved looper applied thereto.

Figure 2 is an enlarged front View of my improved looper with its head portions uppermost.

Figure 3 is a top plan view of the looper shown in Fig. 2.

Figures 4 and 5 are vertical elevations of the looper as seen when looking at the opposite sides of the looper as shown in Fig. 2.

Figures 6 to 9 are diagrammatic illustrations showing different positions of the needle bar and the corresponding positions of the looper in the making of a single stitch.

Figure 10 is a schematic view showing the proper timed relation of the looper to the needle point upon retraction of the needle.

Figure 11 is a side elevation of the special form of the thread carrying needle with which my looper is adapted to operate.

Similar reference characters in the several figures indicate similar parts.

My invention is particularly directed to the construction of a looper employed for tacking or basting, which, for the purpose of speed in handling the material being sewed, the stitches are made in broad steps with interlocking loops capable of being readily unravelled. In this operation it is essential that the thread be drawn tight and I have discovered that by providing a specially constructed looper it is possible to accomplish this object under any tension of thread passing through the needle, with any weight of thread that may be employed and which is capable of operation with light weight cloth.

In order to illustrate my invention I have shown in Fig. 1 a so called tacker head of the Curtis & Marble type used in woolen mills to sew cloth in tubular form, or to unite the edges of two pieces of cloth. The tacker head includes a drive shaft ill, a driven shaft ll carrying a crank disc I2 having a crank pin I3 eccentrically mounted thereon. A needle bar 14 is connected at its upper end to the crank pin l3 and is guided in a rockable bearing I4 adjacent a cloth plate l5 which has the usual opening through which a needle l6 reciprocates. The needle is of special construction as shown in Fig. 11, the eye at its lower end carrying a continuous thread extending from a suitable source and leading from the usual adjustable tension through an eye on the rocking bearing.

Beneath the table I 5 is a shaft 2|] having a hollow forward end for receiving and carrying the shank of the looper which is located in operative relation to the needle, as indicated by A in Fig. 1. The reciprocating oscillating movement of the needle and the continuous rotary movement of the looper is efiected by relatively timed driving 3 connections between the drive shaft Ill and the shafts I l and 20, as will be understood.

From this general arrangement it will be seen by reference to Figs. 6 to 9 that for each complete revolution of the looper the needle bar descends causing the needle to puncture the cloth and by reason of its oscillating movement moves forward with the cloth which in stitching machines of this character is pulled rapidly by leather faced feed rollers.

The needle, as will be seen from Fig. 11, is provided on its forward side with a longitudinal slot 25 extending upwardly from the eye 26 in its point 21 and on its rear side is cut away, as indicated at 28, to form a transverse slot, the bottom of which lies approximately in the median line or axis of the needle. The effect of this slot is to provide the full thickness of the body of the needle surrounding the opening of the eye. It will be seen therefore from this construction that the rear side of the loop of thread which is carried through the overlapping layers of cloth may be readily picked up by the point of the looper which passes between it and the rear side of the needle in the area of the cut away opening 28.

The looper per se is a specially designed cross arm on a shank 30' which latter is secured in the end of shaft 20. The inner face 3! of the cross arm is perpendicular to the axis of the shank 30. One end of this arm constitutes a loop picking head B located a given distance from the axis of the shank and the other a tail or loop spreader C, the extremity of which lies at approximately the same distance from said axis. The outer face 32 of the cross arm is curved, as shown in Figs. 4 and 5. At one end it meets the face 3! at a sharp angle and at the other is spaced from said face sufliciently to provide the metal necessary to support the head B, and is rounded off as indicated at 33. The head B extends at opposite sides of the central plane of the cross arm and at its forward end is provided with a picker point 34 and at its opposite end with a tail 35 for casting off the thread loop.

Looking at Fig. 2 it will be seen that the sides 36 and 31 of the cross arm beneath the head B are shaped on curves 3839 where they merge into head B beneath the picker point 34 and the tail 35, respectively, for easing the movement of the thread loops engaging therewith.

Another feature in the construction of the looper is the channel formed for the accommodation of the end of the needle at the time the head B is picking off the thread loop. Observing Fig. 3 it will be seen that in rear of the point 34 there is a recess 45 which is broad at the top extending well into the tail 35. In line with this recess the edge of the curved face 32 of the cross arm is cut away, as indicated at 46 to leave a free space for the point of the needle, said space extending across the shank 30 of the looper.

The operation of my improved looper may be readily understood by reference to Figs. 6 to 9 in which successive portions of the cloth being sewn are indicated by D. In Fig. 6 the needle bar has moved upward from the previous stitch having left a thread loop E engaged around the looper, so that the thread is held during the retraction of the needle.

In Fig. '7 the needle bar has moved downwardly part way so that the needle point is about to puncture the cloth, the looper spreader C having caused the outer strand of the loop to brush across its curved face 32. The needle enters the cloth to the right of the looper shank 30 and continues downwardly until the needle bar reaches its most extended position as shown in Fig. 8.

The point of the needle carries the thread loop of the succeeding stitch with it below the path of the picker head 13 of the looper. During the dwell occurring upon reversing the direction of travel of the needle the picker point 34 passes through the slot 28 on the rear side of the needle and hooks, the thread to retain it so that as the needle retreats more of the thread is drawn downwardly through its eye. As the needle moves upwardly as shown in Fig. 9, the continued rotation of the looper pulls the thread through the cloth to form the loop, its curved surfaces 38 and 36 causing the loop to slip toward the shank 30- from which it is subsequently cast off by the spreader C.

One of the advantages of the present looper is that in its cycle of operation it has completed the loop by the time the needle reaches its up.- ward excursion. Consequently when the needle begins its downward movement (Fig. 6) to form a succeeding stitch, and puts a tension on the thread, this tension is constant, first, through the needles eye and second during the forming of the loop by the rotation of the looper. In other words the looper ceases to draw the thread while the latter is under the normal tension adjusted for properly allowing it to be unspooled by the" successive advances of the needle. Thus it will be seen that the looper operates at all times on any weight of thread and functions properly under any proper adjustment of the tension on the thread that the needle will handle.

Amongst other features of the looper to which it is desired to call attention are these: The recess or cavity 45 behind the picker point 34 permits this point to pass through the notch 28 of the needle close to the center of the needle. There is a dual advantage in this construction in that the looper will operate to pick up the loop on a coarse cheap thread, generally designated as a string, and the broad upper end of the cavity permits the needle to pass. In fact no harm results if the rear edge of the cavity 45 engages the needle as it is permissible to allow the needle to bend as it is withdrawn. For this reason the operation of the looper is not particularly sensitive as to its timing. Further, the short tail 35 at the rear side of the looper head B effects a quick release or casting off of the thread loop very a close to the needle and in itself does not act to draw down the thread. In the practical operation of the looper it has been found that even when tacking with light or thin cloth a tight stitch results and if an operator runs off the cloth it will not skip stitches.

I claim:

1. A looper comprising a shank, a narrow cross arm on the end of the shank having a flat face on its rear side, a head extending across one end of the arm lying in a plane forward of the rear side of the arm, the forward extremity of the head forming a loop picking point, the other extremity forming a cast off point, the forward side of the arm being bowed outwardly from the head and meeting the rear side of the arm at the opposite side of the shank to form a wedge shaped loop divider, said head in rear of the loop picking point being provided with a needle passage, the latter extending along the side of the arm and across the axis of the shank.

2. A looper comprising ashank, a cross arm thereon having a fiat rear face, a bowed forward face forming a wedge shaped loop spreader at one end of the arm, a straight lateral edge on one side of the arm and a bowed lateral opposing edge creating a narrowed neck portion, a head surmounting the neck curved transversely of the arm with its extremities lying forwardly of the plane of the rear face of the arm, the forward extremity of the head comprising a loop picker point, the other a cast ofi point, said head in rear of the picker point and the underlying lateral edge of the arm being cut away to form a needle passageway.

ROY H. RANDALL.

REFERENCES CITED The following references are of record in the fife Of thi Nmnber s patent:

UNITED STATES PATENTS 

